Tuesday, March 22, 2011

March 22nd, 2011 - Seasons and Sunlight

Today in class, the first thing that we did in class was discuss why we have seasons. We hypothesized that seasons occur because of the Earth tilting different directions and the Earth's position in orbit. Later we learned that the Earth's tilt is always in the same direction and is

constant. The Earth's tilt is always 23.6 degrees if you draw a line from each of the poles.

Next, we discussed direct and indirect sunlight. We already know that the Earth's position around the sun changes making the Earth point either away or towards the sun. The hemisphere tilted towards the sunlight will receive direct sunlight, and the other will receive indirect sunlight. The amount of direct sunlight on the Earth was displayed in

our simulation we did yesterday in the bottom chart with the yellow dot being either spread or focused.

Next, Mr. F had us do an experiment to prove this. Mr. F has a device that measured the amount of solar energy in a room. Then Brady climbed on top of desk and took a solar energy source (a light) and shone it over the device. As Mr. Finley slowly moved the device upwards, the solar energy decreased 0.1. This proves that direct and indirect sunlight is true.

Therefore, seasons occur because of the position the Earth is around the sun. When the Northern hemisphere is receiving indirect sunlight, it is winter while it is summer in the Southern hemisphere. When the Northern hemisphere is receiving direct sunlight, it is summer while it is winter in the Southern hemisphere.